4.13 The Rendering System

The graphics system consists of two or three drivers:

2D Driver or Canvas

This component manages the low-level access to the screen. It supports
primitive functions such as drawing pixels and lines, text output and direct
access to the video memory. There are several implementations of this
component. All are specific to some 3D Rasterizer (for example, the OpenGL 3D
Rasterizer on Unix requires the OpenGL 2D XLib Driver).

Note: You need not load the 2D driver yourself. It is loaded
automatically by the according 3D driver.

3D Rasterizer

This component is required by the 3D Engine but is also useful standalone.
This driver is used to draw 3d graphics and also 2D bitmaps on screen. It
automatically loads a 2D driver on startup. There are currently several
implementations of this component: Software, OpenGL, and Null (for applications
that don't need 3D rendering but still want to use Crystal Space). Additionally
there is also a new OpenGL renderer that is in development right now.

Shader System

Some of the renderers (currently the OpenGL renderer) also require an
additional shader system. When this is present it is possible
to make more advanced texture effects using shaders.